Electrical power generating system

ABSTRACT

An electrical power generating system for providing auxiliary or backup power to a load bus. The system may be used indoors, and generally includes a fuel cell unit comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the fuel cell, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter comprising a first AC output. The system includes a contactor connected between the first AC output and an AC load bus. The AC load bus comprises an AC voltage, and a controller comprising inputs is adapted to sense a phase, a frequency, and a magnitude of the first AC output and the AC voltage and close the contactor when they substantially match.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/745,448 filed on Jan. 17, 2020 which issues as U.S. Pat. No.11,018,508 on May 25, 2021. Each of the aforementioned patentapplications is herein incorporated by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable to this application.

BACKGROUND Field

Example embodiments in general relate to an electrical power generatingsystem for providing safe and efficient backup, emergency, orsupplemental AC power.

Related Art

Any discussion of the related art throughout the specification should inno way be considered as an admission that such related art is widelyknown or forms part of common general knowledge in the field.

Conventional backup electrical generators, especially those suited forrelatively high power output, may comprise diesel or gasoline engines.Such generators are unsuitable for operation in closed spaces, such asinside of buildings, shipboard, in tunnels, etc., due to noiseconsiderations, the danger of storing and handling fuel, and toxicexhaust fumes. Further, many generators are not capable of using abuilding's in-place wiring to provide power within the building.

SUMMARY

An example embodiment is directed to an electrical power generatingsystem. The electrical power generating system includes a fuel cell unitcomprising a first DC output; an electrical storage unit comprising a DCinput coupled to the first DC output of the fuel cell, the electricalstorage unit further comprising a second DC output; an inverter coupledto the second DC output of the electrical storage unit to receive power,the inverter comprising a first AC output; a contactor connected betweenthe first AC output and an AC load bus, the AC load bus comprising an ACvoltage; and a controller comprising inputs adapted to sense a phase, afrequency, and a magnitude of the first AC output and the AC voltage.

The controller controls the phase, the frequency, and the magnitude ofthe first AC output of the inverter. The controller may further comprisean output command to selectively activate the contactor when arelationship between the phase, the frequency, and the magnitude of thefirst AC output and the AC voltage are substantially matched.

In some example embodiments, the controller is usable to adjust thephase, the frequency, and the magnitude of the first AC output of theinverter to cause them to substantially match the phase, the frequency,and the magnitude of the AC voltage on the AC load bus before thecontroller sends the output command. In still other embodiments, thecontroller is further adapted to communicate with a remote computingdevice, which may be a wired or a wireless device. The remote computingdevice is adapted to send a command to the controller to connect theelectrical power generating system to the AC load bus, and it may alsoperform other functions. As an example, the remote computing device maybe adapted to allow a user to monitor operating conditions of theelectrical power generating system. The remote computing device may alsobe adapted to send a command to the controller to disconnect theelectrical power generating system from the AC load bus, or to remotelyshut down the electrical power generating system.

In still other example embodiments of the electrical power generatingsystem activating the contactor causes the first AC output to beconnected in parallel with the AC voltage on the AC load bus.

Still further, the electrical power generating system may comprise asecond fuel cell unit comprising a third DC output, a second electricalstorage unit comprising a second DC input coupled to the third DC outputof the second fuel cell, the second electrical storage unit furthercomprising a fourth DC output. The embodiment may also comprise a secondinverter coupled to the fourth DC output of the second electricalstorage unit to receive power, the second inverter comprising a secondAC output, and a second contactor connected between the second AC outputand the AC load bus, and a second controller comprising second inputsadapted to sense a second phase, a second frequency, and a secondmagnitude of the second AC output and the AC voltage, wherein the secondcontroller controls the second phase, the second frequency, and thesecond magnitude of the second AC output of the second inverter.

The second controller may further comprise a second output command toselectively activate the second contactor when a relationship betweenthe phase, the frequency, and the magnitude of the second AC output andthe AC voltage are substantially matched. In some embodiments,activating the second contactor causes the second AC output to beconnected in parallel with the first AC output.

Further, the second controller may adjust the phase, the frequency, andthe magnitude of the second AC output to cause them to substantiallymatch the phase, the frequency, and the magnitude of the AC voltage onthe AC load bus before the second controller sends the output command.

In an example embodiment, the second controller is further adapted tocommunicate with a remote computing device, which may be the same deviceor a separate device from the one that communicates with the firstcontroller. Further, the remote computing device may be a wired or awireless device. The remote computing device may also be adapted to senda command to the second controller to connect the second AC output tothe AC load bus. For example, the remote computing device may be adaptedto send a command to the second controller to activate or deactivate thesecond contactor.

Further, the remote computing device may be adapted to allow a user tomonitor operating conditions of the electrical power generating system,and specifically, either of two or more generators being used, singly orin parallel, to provide power to the AC load bus. In addition, theremote computing device may be adapted to send a command to the secondcontroller to shut down the second fuel cell.

Using the electrical power generating system may comprise activating thefuel cell, monitoring the phase, frequency, and magnitude of the ACvoltage of the AC load bus, and adjusting the phase, frequency, andmagnitude of the first or second AC output, or both of them, tosubstantially match the phase, frequency, and magnitude of the ACvoltage of the AC load bus, and activating the contactor or contactorsto connect the first, second, or both AC outputs to the AC load bus.There has thus been outlined, rather broadly, some of the embodiments ofthe electrical power generating system in order that the detaileddescription thereof may be better understood, and in order that thepresent contribution to the art may be better appreciated. There areadditional embodiments of the electrical power generating system thatwill be described hereinafter and that will form the subject matter ofthe claims appended hereto. In this respect, before explaining at leastone embodiment of the electrical power generating system in detail, itis to be understood that the electrical power generating system is notlimited in its application to the details of construction or to thearrangements of the components set forth in the following description orillustrated in the drawings. The electrical power generating system iscapable of other embodiments and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein are for the purpose of the description andshould not be regarded as limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will become more fully understood from the detaileddescription given herein below and the accompanying drawings, whereinlike elements are represented by like reference characters, which aregiven by way of illustration only and thus are not limitative of theexample embodiments herein.

FIG. 1 is a simplified block diagram of an electrical power generatingsystem in accordance with an example embodiment.

FIG. 2 is another simplified block diagram of an electrical powergenerating system in accordance with an example embodiment.

FIG. 3 is a perspective view illustrating a use of an electrical powergenerating system in accordance with an example embodiment.

FIG. 4 is another perspective view illustrating a portable electricalpower generating system in accordance with an example embodiment.

FIG. 5 is another perspective view illustrating a portable electricalpower generating system in accordance with an example embodiment.

FIG. 6 is a simplified flow chart illustrating operation of anelectrical power generating system in accordance with an exampleembodiment.

FIG. 7 is another simplified block diagram of an electrical powergenerating system in accordance with an example embodiment.

FIG. 8 is another simplified flow chart illustrating a use of anelectrical power generating system in accordance with an exampleembodiment.

FIG. 9 is a front view of a display usable with an electrical powergenerating system in accordance with an example embodiment.

FIG. 10 illustrates voltage waveforms of an electrical power generatingsystem in accordance with an example embodiment.

FIG. 11 is another illustration of voltage waveforms of an electricalpower generating system in accordance with an example embodiment.

FIG. 12 is another illustration of voltage waveforms of an electricalpower generating system in accordance with an example embodiment.

DETAILED DESCRIPTION

A. Overview.

An example electrical power generating system 10 generally comprises afuel cell unit 30 comprising a first DC output 32, an electrical storageunit 40 comprising a DC input 42 coupled to the first DC output 32 ofthe fuel cell unit 30, the electrical storage unit 40 further comprisinga second DC output 44, an inverter 50 coupled to the second DC output 44of the electrical storage unit 40 to receive power, the inverter 50comprising a first AC output 52, a contactor 60 connected between thefirst AC output 52 and an AC load bus 66, the AC load bus 66 comprisingan AC voltage, and a controller 70 comprising inputs 62, 64 adapted tosense a phase, a frequency, and a magnitude of the first AC output 52and the AC voltage on the load bus 66, respectively.

The controller 70 controls the phase, the frequency, and the magnitudeof the first AC output 52 of the inverter. The controller 70 may furthercomprise an output command 72 to selectively activate the contactor 60when a relationship between the phase, the frequency, and the magnitudeof the first AC output 52 and the AC voltage are substantially matched.

In some example embodiments, the controller 70 is usable to adjust thephase, the frequency, and the magnitude of the first AC output 52 of theinverter 50 to cause them to substantially match the phase, thefrequency, and the magnitude of the AC voltage on the AC load bus 66before the controller 70 sends the output command. In still otherembodiments, the controller 70 is further adapted to communicate with aremote computing device 95, which may be a wired or a wireless device.The remote computing device 95 is adapted to send a command to thecontroller 70 to connect the electrical power generating system 10 tothe AC load bus 66, and it may also perform other functions. As anexample, the remote computing device 95 may be adapted to allow a userto monitor operating conditions of the electrical power generatingsystem 10. The remote computing device 95 may also be adapted to send acommand to the controller 70 to disconnect the electrical powergenerating system 10 from the AC load bus 66, or to remotely shut downthe electrical power generating system 10.

In still other example embodiments of the electrical power generatingsystem 10, activating the contactor 60 causes the first AC output 52 tobe connected in parallel with the AC voltage on the AC load bus 66,which is possible due to the synchronization of the voltage parametersas discussed above.

Further, the electrical power generating system 10 may include more thanone power source subsystem, such as a second fuel cell, inverter, andthe other components mentioned above, and the components or subsystemscan be connected in parallel. As an example, two or more subsystems ofthe present system 10 may be connected in parallel over an AC load bus66, such as a building or house's existing wiring, effectively usingthat wiring as a micro-microgrid. In such a case, one, two, or moresubsystems can be connected to the AC load bus 66 while the bus is alsopowered by an AC main power source 90, such as a city's electrical grid,with the electrical power generating system 10 adding additional, localpower capacity to the wiring.

The system 10 can also be used to provide backup or emergency power tothe AC load bus 66 with no other power source available. Use of existingwiring as a micro-microgrid is possible because the system uses analogpower line synchronization for matching or substantially matchingvoltage, frequency, and phase of the generated AC output to any voltagepresent on the existing AC load bus, either from the AC main source 90or another fuel cell/inverter of system 10 connected in parallel. Anelectrical power generating system 10 of the present system may compriseone or more generators, since each may be substantially the same, andbecause each may be connected to the AC load bus 66 at the same time,thus becoming part of the overall system 10.

For indoor operations, the system 10 can be entirely contained on aportable, wheeled cart 14, sized to readily fit through doorways andhallways of hotels, industrial buildings, etc. Furthermore, the systemcan easily be connected to existing building wiring (e.g., conventionaland standard 120V building or residential wiring) by providing an outputin the form of standard 120V power cords that can simply be plugged intoone or more power outlets of the existing wiring system, thus using theexisting wiring as a micro-microgrid with no special wiring equipmentneeded.

The system also includes a telemetry component 80 for remote monitoringand system management. For example, parameters such as run time, fuelamount, power output, output voltage, output current, etc., may bemonitored via telemetry. The telemetry component 80 also allows theremote computing device 95, such as a wireless phone, laptop, desktopcomputer, etc., to remotely start the system or any subsystem, shut downthe system, or to connect or disconnect any individual contactor orgroup of contactors to the micro-microgrid.

One possible physical configuration of the electrical power generatingsystem 10, or a subsystem (if more than one generating unit is to beused to supply power) is shown in FIGS. 4 and 5. As shown in FIG. 4, allthe components of a single unit can be mounted on a wheeled cart 14 thatis sized to fit in doorways and hallways of buildings, such as hotels orcommercial establishments. One possible arrangement of the majorphysical components is shown in FIG. 5, which is also representative ofthe main components shown in FIG. 1. The power output of an electricalpower generating system 10 can be supplied over ordinary power cordsthat can be plugged into a building's existing outlets, as shown in FIG.3, so that no special connections are required for the supply ofauxiliary or emergency power.

B. Fuel Cell Unit.

The electrical power generating system 10 may make use of compressedhydrogen gas 20 as a source for the fuel cell unit 30. Compressedhydrogen gas is readily available from industrial gas suppliers. Thehydrogen gas 20 is kept in a storage tank or tanks of the system 10, andis regulated to low pressures and provided over a supply line 26 to afuel cell unit 30, as generally shown in FIG. 1. Compressed hydrogen gasis easy to use and transport, and provides for economical operation ofthe fuel cell unit 30.

For indoor use, using purified hydrogen as a fuel source for the inputof a fuel cell or cells has distinct advantages over other sources. Forexample, some fuel cell systems use or propose reformers to providehydrogen from a liquid feedstock. However, the turn-on time forreformers is relatively long. For example, based on currenttechnologies, it may take eight to twelve hours to reach thetemperatures needed to produce hydrogen from a liquid feedstock.

This time may be reduced if a heater is continually operated, butcontinuous use of a heater may consume, for example, 200 W to 500 W instandby mode without any productive use being made of the system, thusgreatly reducing the overall efficiency, especially for a system used toproduce, for example, a relatively small amount of power, such as 2 kW.

Further, the process of reforming liquid fuel is not zero emission, andproduces CO and CO₂, which can be dangerous in indoor or confinedenvironments. In contrast, hydrogen fuel cells produce no harmfulemissions, so there is no need to store or otherwise dispose of anybyproducts or toxic fuel. Hydrogen fuel cells have a proven track recordof safe indoor use, such as fuel-cell powered forklifts in materialhandling applications. Furthermore, compressed hydrogen systems arerelatively compact, and can, for example, allow an entire 2 kW to 8 kWsystem to be constructed on a portable cart 14 that will easily fitthrough hotel and building doorways and hallways.

Despite the advantages of using compressed hydrogen gas 20, the systemmay alternatively use a different fuel 22 in combination with a hydrogengenerator 24, as also shown in FIG. 1. The output of the hydrogengenerator 24 is fed to the fuel cell unit 30 by alternate supply line26, just as in the case where hydrogen gas is used directly. As anexample, methanol can be used as a feedstock to produce hydrogen. Oncethe hydrogen fuel is produced in the alternative embodiment, operationof the system is substantially the same.

In an example embodiment, the fuel cell unit 30 may comprise multiplefuel cells, which are designed to achieve the total voltage output andpower desired. In each fuel cell of a fuel cell unit that uses hydrogenas fuel, electricity is generated with no combustion or harmfulbyproducts, by an electrochemical reaction that uses, for example, astack of proton exchange membrane (PEM) fuel cells. PEM fuel cells havea high power density and operate at relatively low temperatures; as aresult, they allow the fuel cell unit to quickly warm up and begingenerating electricity. Other fuel cell technologies may also be usedwith the present system, such as alkaline fuel cells, zinc oxide,phosphoric acid fuel cells, molten-carbonate, solid oxide, etc.

C. DC to AC Conversion.

The electrical storage unit 40 is the first part of the system toreceive power from the fuel cell 30, and it provides for storage of DCpower that is to be provided to the inverter 50 for conversion to ACpower. The electrical storage unit 40 may comprise a battery or bank ofbatteries, which receive and store DC electrical power to be provided tothe inverter 50, as also shown in FIG. 1. Electrical storage unit 40receives power from the fuel cell at DC input 42, as shown, and providespower via DC outputs 44, which are coupled electrically (conductively)to inverter 50. Electrical storage unit 40 may comprise multiplehigh-capacity, high-power rechargeable batteries and a battery chargingsystem (not shown), which receives input power from the fuel cell unit30 and conditions it in order to keep the batteries of the storage unit40 optimally charged. Electrical storage unit 40 may also be used topower the controller 70, as well as other components of system 10, uponstartup of the system.

In addition, since the electrical storage unit 40 is connected to theinverter 50, the unit 40 provides power to the inverter 30 along withthat provided by the fuel cell unit 30, and thus may help the systemmeet higher transient power demands if the instantaneous power demandedof the system exceeds the capacity of the fuel cell unit 30. Theelectrical storage unit 40 also acts as an energy buffer, helping toprovide a smooth any variability in the output of the fuel cell unit 30before it reaches the inverter 50.

The inverter 50 may comprise a single inverter, or it may comprise twoor even more units connected and controlled to operate in parallel. Inany configuration, the inverter 50 is operated under the control ofcontroller 70 to provide an adjustable, preferably sinusoidal AC outputvoltage 52 that can be controlled in phase, frequency, and voltage tomatch a voltage present on an AC load bus 66, such as building wiring,as best shown in FIGS. 1 and 2. More specifically, the output of theinverter 50, once synchronized, may readily be connected directly to astandard 120/240 volt National Electrical Code building wiring system,and can in fact use the existing wiring as a micro-microgrid which canprovide power from any of a number of sources to any AC load connectedto the wiring system.

The use of a battery (e.g., storage unit 40) in the system provides alocal means to store energy produced by the fuel cell unit 30 beforebeing consumed by the electrical loads being powered. The storage unit40 then provides instantaneous energy delivery, which provides asmoothing function for the load as the electrical demand changes inmagnitude. The storage unit 40 also provides startup power for the fuelcell unit 30 prior to the consumption of hydrogen for electricalproduction. The output of the storage unit 40 provides inputs to theinverter 50 for the production of AC power as well directly providing DCpower (either at voltage at the potential level of the batteries or atany other DC voltage via the means of a DC/DC voltage converter,regulator, or voltage division circuitry.)

For applications where the delivered energy is to be an AC waveform,inverter(s) are integrated to convert the DC electricity to ACwaveforms. The AC waveform may be of selectable or adjustable voltage(for example, 120V or 240V), of selectable or adjustable frequency (forexample, 50 Hz or 60 Hz), or phases (for example, single phase or threephase). In certain applications, multiple inverters 50 may be employedto create a plurality of AC voltages, where the settings of the firstinverter (for example, 120V, 60 Hz, single phase) may be different thanthe settings of the second inverter (for example 240V, 50 Hz, threephase).

D. Controller.

The controller 70 performs synchronization and control functionsnecessary for operation of the system 10. Before the system is startedand running, the electrical storage unit 40 provides power to thecontroller 70, which may be off until a power or start button ispressed, at which point the controller begins to operate. The controller70 may control valves and regulators (not shown) used to activate thefuel cell 30. The controller 70 also receives AC voltage inputs tomonitor and control the output of the system, as shown in FIGS. 1 and 2.For example, the controller receives AC input 62 from the output ofinverter 50, to monitor and control the phase, frequency, and magnitudeof the inverter 50. The controller 70 may comprise an analogsynchronizer to bring these voltage parameters into substantialsynchronization with the AC voltage on the AC load bus 66, monitored atinput 64 of the controller 70. Additional details regardingsynchronization and thresholds for closing contactor 60 may be found inU.S. Pat. No. 7,180,210, which is hereby incorporated by reference.

The controller also provides an output command 72 to selectivelyactivate or deactivate a contactor 60. As shown in FIGS. 1 and 2,contactor 60 is operable to connect and disconnect the AC output 52 ofthe portable electrical power generating system 10 from the AC load bus66. Although the contactor is shown in the figures as having twocontacts, different configurations are also possible. For example, thecontactor 60 may be configured to connect or disconnect just the activevoltage line, with neutral being directly connected. In addition, thesystem is shown as supplying a single phase, but in practice the systemmay be used with multiple phases or to supply both sides of a 240-volt(three-wire) configuration.

As discussed in greater detail below, when the AC output 52 of theinverter 50 is connected to the AC load bus 66, it is done in a “makebefore break” manner, such that the AC output 52 is connected inparallel with the voltage already present on the load bus 66, whichrequires the synchronization, or substantial matching, of the voltageoutput 52 to the voltage on the load bus 66.

In addition to the output control functions, the controller 70 may alsobe adapted to interface with, or to include, a telemetry component 80.If the telemetry is a separate component, it can be adapted tocommunicate with the controller 70 via an internal communication link74, which may be in various forms, such as wired or wireless analogand/or digital links. In addition to the automatic functions of thecontroller 70, the system 10 can use telemetry for remote monitoring andcontrol, which can be done over a communications link 82, such as an airinterface and internet connection, by way of non-limiting example. Anoverview of the remote monitoring and control functionality is bestillustrated in FIG. 7, which shows a remote computing device, such as asmart phone, tablet, laptop or desktop computer, etc., in communicationwith three portable generating subsystems A, B, and C, which comprise anelectrical power generating system 10 which is connectable to the loadbus 66. As mentioned above, each subsystem A, B, and C may be configuredsubstantially as the single unit shown in FIG. 1, which is possiblebecause each subsystem can be connected in parallel, and can operateindependently. Accordingly, element numbers followed by letters, such as62A, are directly equivalent to numbers with no letters, such as 62, asrepresented in FIG. 1.

As also shown in FIG. 7, the controller of each subsystem receives ACvoltage inputs to monitor and control the output of the system, and tosynchronize all units with the voltage on the load bus 66.Alternatively, the system may power an otherwise unpowered load bus(e.g., with no AC main source connected) to provide auxiliary,emergency, or backup power.

In the embodiment of FIG. 7, each subsystem receives AC inputs 62A, 62B,or 62C from the output of each inverter, to monitor and control thephase, frequency, and magnitude of the inverter as described above. Eachcontroller 70 may then bring the voltage parameters into substantialsynchronization with any AC voltage on the AC load bus 66, monitored atinputs 64A, 64B, and 64C, as shown. As with the single system connectionof FIG. 1, each subsystem A, B, or C controls its own contactor, 60A,60B, and 60C, respectively, in order to connect or disconnect thesubsystem AC inverter output from the bus, again using the load bus 66to substantially synchronize of substantially match the voltageparameters so that the systems can be connected in parallel.

FIG. 2 illustrates the system with two subsystems A and B connectable inparallel, where either or both subsystem can provide power to the loadbus 66, either in addition to or in lieu of AC main power source 90, inorder to power load or loads 92. As with the singe system of FIG. 1,each subsystem includes an input 62A or 62B (directly equivalent toinput 62 of FIG. 1) to monitor and control the inverter output voltage,as well as inputs 64A and 64B to monitor the AC load bus voltage forcontrol purposes. In addition, each subsystem, A, B, has control over acontactor 60A or 60B to connect and disconnect the AC output voltage toor from the load bus 66, using control outputs 72A or 72B, as shown.Since FIG. 2 simply illustrates two of the systems shown in FIG. 1,connectable in parallel, the labels appended with “A” and “B” aredirectly equivalent to the inputs, outputs, etc., without thosedesignations as shown in FIG. 1.

In this configuration, both subsystems can be used to supply power inparallel with the AC main source 90, or alternatively, to supply powerto bus 66 with no AC main power available, in which case subsystem A andB would be synchronized with each other. For telemetry, subsystem A mayuse communication link 82A, and subsystem B may use communication link82B, to receive commands and allow for remote monitoring and control ofthe system.

As shown in FIG. 2, two or more systems may be connected at the AC levelvia a means of synchronization to collectively supply the energyconsumed by the electrical loads. The load sharing between two (or more)fuel cell systems allows the fuel cells to collectively supply theenergy demanded by the load, where the instantaneous load is powered bythe storage unit 40 connected to the loads via the inverter(s) 50, andthe fuel cell(s) recharge the storage unit 40 to full capacity.

E. Operation of Preferred Embodiment.

In use, the electrical power generating system 10 may be connected toexisting building wiring as shown for example in FIGS. 1-3. To startusing the system, as outlined generally in FIG. 6, a power button (notshown) may be pressed, which applies power to the controller 70,activating the system, which in turn automatically starts the fuel celloperation. Until the fuel cell unit is up and running normally (i.e.,providing a DC output to the electrical storage unit 40 and the inverter50) the electrical storage unit 40 can provide power to the system,including the controller 70. At this stage, by default, contactor 60 isdeactivated. The controller then begins to monitor the phase, frequency,and voltage of the AC main power—that is, the voltage on the load bus66, as well as those same parameters at the output of the inverter 50.Initially, there will be a difference in the parameters. For example, asshown in FIGS. 10, 11, and 12, there may be a difference in the voltage,the phase, and the frequency, respectively, between the bus voltage andthe AC output 52 of the inverter 50. In the figures, these differencesare indicated by the arrows.

The controller 70 will continue to monitor the voltages and adjust theoutput of the inverter 50 until the variable voltage parameters of theinverter 50 are within an acceptable threshold. This will allowcontactor 60 to be closed, paralleling the two or more voltage sourceswithout creating large transients on the load bus 66. For example, thefrequency and the voltage may be matched to a close degree, such aswithin a few percent of each other. For phase, an acceptable thresholdmight be a phase difference of 5° or less, with the variable phase ofthe inverter voltage output 52 approaching, rather than moving awayfrom, the phase of the voltage on the load bus 66. Other phasedifferences are also possible, and larger differences may be used,especially if the closing timing is performed by a circuit that detectszero crossings of the AC waveform to close the contactor 60 at or nearzero crossings.

Once the AC output voltage 52 is within acceptable limits, thecontroller 70 will send a command to contactor 60 to connect theelectrical power generating system 10 to the AC load bus 66, parallelingthe inverter output with AC main power. This operation is the samewhether there is just one, or multiple, subsystems connected to providepower, as shown for example in FIGS. 1-3.

As mentioned above, the telemetry component 80, which may be incommunication with controller 70 via link 74, also allows for remotemonitoring and management of the system 10. It allows a user or users tomonitor and control the system easily using a remote computing device95, such as a smart phone, a tablet, a laptop, or a desktop computer, asjust a few examples. The system 10 may communicate with the remotecomputing device 95 via one or more communications or telemetry links82. Parameters such as run time, remaining fuel amount, power output,output voltage, output current, operating temperature, etc., may bemonitored via telemetry component 80, with the information presentedgraphically or in table form, for example, at device 95. The operatingdata may also be stored locally or in remote device 95 for referencelater. In addition, remote computing device 95 may be used to controlthe system. Specifically, a user may remotely initiate startup,shutdown, connection, or disconnection of the electrical powergenerating system 10 from the load bus 66.

FIGS. 3, 8, and 9 represents a particular use of the system 10, which isto provide auxiliary power capacity to building wiring where a higherthan normal load 92 is connected to the AC load bus 66. As shown in thefigures generally, an entire system 10 is typically mounted on a single,portable unit 14, such that it can be easily moved into place, and willfit through doorways and hallways.

In the illustration, the load 92 is a high powered (e.g., >6 kW) heaterusable for pest remediation in hotel rooms or bedrooms. As shown in FIG.3, the output of system 10 can be connected through ordinary poweroutlets in a room adjacent to the room with the extra load, in order touse the building wiring 66 as a micro-microgrid. On the load side, theload 92 is also simply plugged in to existing outlets in the room beingtreated, as shown. No special or additional connections are needed,although it may be noted that the building wiring system, without theaddition power of electrical power generating system 10, may not becapable of continuously supplying the power needed at load 92. Note thatthe connections of FIG. 3 are exemplary of a particular use, althoughother uses, such as backup and emergency power generation, are alsopossible as explained herein. For pest remediation, the system 10 mayhave a custom display 12 to show system operating conditions during theremediation, as shown in FIG. 9.

In particular, for pest remediation using heat, it is required that aminimum temperature is reached and maintained to kill the pests. Toensure effective operation in this regard, the system 10 can receive,via wires or wirelessly, inputs from one or more temperature sensors 94in the room to be treated. The electrical power generating system 10 canbe configured to monitor and display the conditions on a display unit 12during this process. The overall process is outlined in FIG. 8, andbegins with connecting one or more electrical power generating systems10 to the building wiring, as shown in FIG. 3.

Next, one or more temperature sensors, such as wireless sensors 94, maybe placed in the room. As an example, they may be spaced apart toprovide a good average temperature, and to ensure there are no coldspots—in other words, to ensure that every location in the room meetsthe temperature requirements for remediation. The system 10 willcontinue to monitor temperatures and provide power to the heater (load92) until a minimum temperature, such as 125° F., is reached by everysensor 94.

Once lethal temperature is reached as indicated by all the temperaturesensors 94, a dwell timer is started, and a visual cue is displayedalong with the dwell time, on display 12. This allows a user to veryeasily see how long the lethal temperature has been applied to the roombeing treated, and to determine if remediation can be consideredcomplete. Note that the parameters shown in FIG. 9 can also easily bedisplayed remotely on remote computing device 95. The display 12 mayalso display the output power level and the total system operating time,as also shown in FIG. 9.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar to or equivalent to those described herein can be used in thepractice or testing of the electrical power generating system, suitablemethods and materials are described above. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety to the extent allowed byapplicable law and regulations. In the event of inconsistent usagesbetween this document and those documents so incorporated by reference,the usage in the incorporated reference(s) should be consideredsupplementary to that of this document; for irreconcilableinconsistencies, the usage in this document controls. The electricalpower generating system may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof, and it istherefore desired that the present embodiment be considered in allrespects as illustrative and not restrictive. Any headings utilizedwithin the description are for convenience only and have no legal orlimiting effect.

What is claimed is:
 1. An electrical power generating system,comprising: a fuel cell comprising a first DC output; an electricalstorage unit comprising a DC input coupled to the first DC output of thefuel cell, the electrical storage unit further comprising a second DCoutput; an inverter coupled to the second DC output of the electricalstorage unit to receive power, the inverter comprising a first ACoutput; a contactor connected between the first AC output and an AC loadbus, wherein the AC load bus has an AC voltage; and a controller adaptedto sense a phase and a frequency of the first AC output and the ACvoltage of the AC load bus, wherein the controller controls the phaseand the frequency of the first AC output of the inverter; wherein thecontroller further comprises an output command to selectively activatethe contactor when a relationship between the phase and the frequency ofthe first AC output and the AC voltage are substantially matched;wherein the controller is further adapted to communicate with a remotecomputing device.
 2. The electrical power generating system of claim 1,wherein the controller is usable to adjust the phase and the frequencyof the first AC output of the inverter to cause them to substantiallymatch the phase and the frequency of the AC voltage on the AC load busbefore the controller sends the output command.
 3. The electrical powergenerating system of claim 1, wherein the remote computing devicecomprises a wireless device.
 4. The electrical power generating systemof claim 1, wherein the remote computing device is adapted to send acommand to the controller to connect the electrical power generatingsystem to the AC load bus.
 5. The electrical power generating system ofclaim 1, wherein the remote computing device is adapted to allow a userto monitor operating conditions of the electrical power generatingsystem.
 6. The electrical power generating system of claim 1, whereinthe remote computing device is adapted to send a command to thecontroller to disconnect the electrical power generating system from theAC load bus.
 7. The electrical power generating system of claim 1,further comprising: a second fuel cell comprising a third DC output; asecond electrical storage unit comprising a second DC input coupled tothe third DC output of the second fuel cell, the second electricalstorage unit further comprising a fourth DC output; a second invertercoupled to the fourth DC output of the second electrical storage unit toreceive power, the second inverter comprising a second AC output; asecond contactor connected between the second AC output and the AC loadbus; and a second controller comprising second inputs adapted to sense asecond phase and a second frequency of the second AC output and the ACvoltage, wherein the second controller controls the second phase and thesecond frequency of the second AC output of the second inverter; whereinthe second controller further comprises a second output command toselectively activate the second contactor when a relationship betweenthe phase and the frequency of the second AC output and the AC voltageare substantially matched.
 8. A method of using the electrical powergenerating system of claim 1, comprising: activating the fuel cell;monitoring the phase and frequency of the AC voltage of the AC load bus;adjusting the phase and frequency of the first AC output tosubstantially match the phase and frequency of the AC voltage of the ACload bus; and activating the contactor to connect the first AC output tothe AC load bus.
 9. An electrical power generating system, comprising: afuel cell comprising a first DC output; an electrical storage unitcomprising a DC input coupled to the first DC output of the fuel cell,the electrical storage unit further comprising a second DC output; aninverter coupled to the second DC output of the electrical storage unitto receive power, the inverter comprising a first AC output; a contactorconnected between the first AC output and an AC load bus, wherein the ACload bus has an AC voltage; and a controller adapted to sense a phase ofthe first AC output and the AC voltage, wherein the controller controlsthe phase of the first AC output of the inverter; wherein the controllerfurther comprises an output command to selectively activate thecontactor when a relationship between the phase of the first AC outputand the AC voltage are substantially matched; wherein the controller isfurther adapted to communicate with a remote computing device.
 10. Theelectrical power generating system of claim 9, wherein the controller isusable to adjust the phase of the first AC output of the inverter tocause the phase of the first AC output of the inverter to substantiallymatch the phase of the AC voltage on the AC load bus before thecontroller sends the output command.
 11. The electrical power generatingsystem of claim 9, wherein the remote computing device is adapted tosend a command to the controller to connect the electrical powergenerating system to the AC load bus.
 12. The electrical powergenerating system of claim 9, wherein the remote computing device isadapted to allow a user to monitor operating conditions of theelectrical power generating system.
 13. The electrical power generatingsystem of claim 9, wherein the remote computing device is adapted tosend a command to the controller to disconnect the electrical powergenerating system from the AC load bus.
 14. A method of using theelectrical power generating system of claim 9, comprising: activatingthe fuel cell; monitoring the phase of the AC voltage of the AC loadbus; adjusting the phase of the first AC output to substantially matchthe phase of the AC voltage of the AC load bus; and activating thecontactor to connect the first AC output to the AC load bus.
 15. Anelectrical power generating system, comprising: a fuel cell comprising afirst DC output; an electrical storage unit comprising a DC inputcoupled to the first DC output of the fuel cell, the electrical storageunit further comprising a second DC output; an inverter coupled to thesecond DC output of the electrical storage unit to receive power, theinverter comprising a first AC output; a contactor connected between thefirst AC output and an AC load bus, wherein the AC load bus has an ACvoltage; and a controller adapted to sense a phase and a magnitude ofthe first AC output and the AC voltage, wherein the controller controlsthe phase of the first AC output of the inverter; wherein the controllerfurther comprises an output command to selectively activate thecontactor when a relationship between the phase and the magnitude of thefirst AC output and the AC voltage are substantially matched; whereinthe controller is further adapted to communicate with a remote computingdevice.
 16. The electrical power generating system of claim 15, whereinthe controller is usable to adjust the phase and the magnitude of thefirst AC output of the inverter to cause them to substantially match thephase and the magnitude of the AC voltage on the AC load bus before thecontroller sends the output command.
 17. The electrical power generatingsystem of claim 15, wherein the remote computing device comprises awireless device.
 18. The electrical power generating system of claim 15,wherein the remote computing device is adapted to send a command to thecontroller to connect the electrical power generating system to the ACload bus.
 19. The electrical power generating system of claim 15,wherein the remote computing device is adapted to allow a user tomonitor operating conditions of the electrical power generating system.20. The electrical power generating system of claim 15, wherein theremote computing device is adapted to send a command to the controllerto disconnect the electrical power generating system from the AC loadbus.